West Sussex Trading Standards is warning all poultry keepers they must follow housing restrictions to prevent the spread of avian flu.
It comes after two confirmed cases of avian flu in the UK in domestic 'back yard' chicken flocks.
Government restrictions require all poultry keepers to move birds into a suitable building away from wild birds.
If that is not possible, owners must take sensible precautions.
Putting up netting to create a temporary enclosure; and
Keeping food and water supplies inside where wild birds cannot contaminate them.
Trading Standards Manager Peter Aston said: “Initial outbreaks in the UK were in commercial premises, but the last two have been in hens kept at peoples’ homes.
"In both cases the owners ignored the restrictions on keeping them separated from contact with wild birds.
"The result was the destruction of those birds and restrictions placed on commercial premises around them.”
He added: “It’s really important keepers of domestic poultry play their part in preventing the spread of Avian Flu by observing the restrictions.
"Otherwise, not only do they risk losing their birds to the virus, they risk causing commercial poultry businesses to lose theirs too.
"This could have a devastating effect on the county's economy.
“Trading Standards Officers will consider enforcement action against any poultry keeper refusing to follow restrictions."
If you notice someone keeping poultry in the open, let Trading Standards know.
You can contact them using the online reporting form here.
You can leave information anonymously.
Further information on avian flu and the current restrictions is available here.